U.S. Pat. No. 3,130,584 describes a probe for taking gas samples and heat measurements in a shaft furnace.
Given the extremely severe working conditions of these probes, they require frequent maintenance, for example in order to replace a faulty thermocouple or unplug a blocked pipe for taking gas samples. In order to carry out these maintenance operations, it was hitherto necessary to disassemble the probe completely and to carry out this work, more often than not, in the repair shop, which, of course, constitutes a loss of time.